In many battle fields, when it is necessary to protect the troops, trenches are being dag, or protective walls are being erected. For many years, the protective walls were made of sacks filled with local earth or sand. This system is very cheap and easy to implement since it can be carried out by relatively small sacks that, when filled, can be easily carried out by a person. Thus, if enough sacks are piled, they enable enough protection against light and medium flat-trajectory weapons like rifles and machine guns.
In many armed conflict zones around the world, there is a need to protect the military forces from being injured by steep-trajectory weapons, like rockets, missiles, and mortars. In this case, piling of sacks filled with earth or sand is not satisfactory since there is a need to supply enough protection from the upper side as well.
A large variety of structures and solutions are used, such as shelters, bunkers or other types of constructed buildings. Despite the fact that these structures provide the necessary protection, they suffer from various disadvantages; they are very expensive, require a large erection time, and cannot be re-used in another site.
In order to provide a sheltering structure that protects against steeptrajectory weapons, various solutions are known in the market. A structure known as “Mivtsar Yehuda” (namely, Yehuda Fortress) by Yehuda Fences Ltd. (www.yfence.co.il), is a military fortification structure that is designed for fast erection for protection of a maritime container in the size of 600×250×250 cm. The “Mivtsar Yehuda” consists of elements that are constructed of a galvanized steel net envelope, and an inner sheet made of a UV protected geo-textile cloth. When these elements are filled with earth, they form a bulged box-like shape. Placing the filled elements one adjacent the other enables to erect a protective structure around the container. However, a main disadvantage of this structure is that the basic elements cannot be used directly for building a protective roof. Thus, in order to enable placing of the earth-filled elements as a protective roof, first, a special steel structural frame has to be erected, whether it is a one-piece structure, or, a modular structure made of steel beams, rods and plates that are modularly connected to each other in order to form a strong structure that can withstand a high load thereon without collapsing. Second, the steel structural frame is placed on the previously erected structure of filled elements, and then, third, new filled elements are placed on the structural frame to be used as a protective roof. Since the structural frame has a relatively high height in order to withstand the heavy loads apply thereon, it exposes the protected item, in this case, the container, to medium inclination trajectory exploding items. Thus, it is necessary to form the structural frame large enough, i.e., with a large overlapping relative to the vertical walls made by the filled elements, in order to assure that the container is well protected from the top side. Furthermore, if an explosive charge falls and explodes adjacent the entrance to the protected area, there is a direct line of explosion towards the protected area. This problem could be avoided just with addition of a substantial number of filled elements.
HESCO Bastion Ltd. (www.hesco.com), based in the UK, manufactures a force protection product known as a Concertainer unit. The Concertainer unit is a multi-cellular wall system manufactured from welded Zinc-Alu coated steel wire mesh and joined with vertical, helical coil joints. The units are lined with heavy-duty non-woven polypropylene geotextile. The concertainer units use locally available fill material to rapidly construct defensive barriers and other structures with minimal manpower and resources. The concertainer units can be extended and joined together to provide effective and economical structures according to threat needs and level of protection required. A rapid in-theatre deployment utilizes a specially designed and engineered container to provide a significant increase in the quantity of concertainer units that can be transported in a 20 ft ISO container footprint. HESCO have developed the HLBR (HESCO lightweight bunker roof), a rapid and easily erectable lightweight roof specifically designed to provide protection against IDF weapons. The roof can be built on almost any walls capable of taking the load that the roof will impose upon it. Again, this roof is a specially built item in order to withstand the load applied thereon, and it cannot be made from the same units that form the walls.
An HESCO bunker set has been developed to utilize 40 ft and 20 ft ISO containers. Walls are constructed using specifically adapted Mil 1 Concertainer units to give a protective wall thickness of in excess of 1 m. The roof design provides 0.6 m of overhead cover. Material bunkers provide access from one end of the bunker, while personnel bunkers provide access from both ends. Again, in this design, the roof cannot utilize the same units forming the walls.